With the increasing of multi-media information search devices, people use touch screens more and more. The touch screens can not only be used for multimedia information search, but also have advantages such as being firm and durable, quick reaction, saving space and communication friendly. By way of the touch screen technology, a user can operate a host machine as long as a finger slightly touches an icon or character at the display screen of a computer, and thereby Human-Computer Interaction is more direct. The technology brings much convenience to a user who does not understand computer operation.
According to working principles and media of information transmission of the touch screens, the touch screens can be divided into four types: resistance type, capacitance induction type, infrared ray type and surface sound wave type. An infrared touch screen is not interfered by electric current, voltage or static electricity, and is adapted to severe environments, thus an infrared ray technology is one of the development tendencies of touch screen products.
Traditional infrared touch screens usually are provided with a circuit board frame in front of a display screen, for the circuit board frame, infrared emitting tubes are arranged at two adjacent sides of a quadrilateral screen, and infrared receiving tubes are arranged at the other two adjacent sides of the quadrilateral screen. Generally, the infrared emitting tubes and the infrared receiving tubes are respectively located at two sides of the screen opposite to each other, and the infrared emitting tubes and the infrared receiving tubes are arranged corresponding to each other one by one. The infrared emitting tubes emit infrared ray and the infrared receiving tubes receive the infrared ray so as to form infrared matrixes, arranged densely in directions X and Y, which are used to detect and locate a user's touch. The traditional infrared touch screens have a complex structure, require high design accuracy, also, due to a large number of the infrared emitting tubes, the power consumption of the touch screen is relative large.